Thermocouple



Patented Sept. 27, 1927'.

UNITED STATES 1,643,134 PATENT oFFicE. i

VLADIMIR K. ZW ORYKIN, OF KANSAS CITY, MISSOURI, ASSIGNOR TO C & C DEVELOP- ING COMPANY, OF KANSAS CITY, MISSOURI A CORPORATION OF ARIZONA.

THERMOCOUPLE.

Application led June 19,

The present invention relates to electrical apparatus, and aims to provide a new and improved thermocouple struct-ure as well as a novel and efficient method or process of constructing the same.

Accordingly, I have devised an improved form of thermocouple element which comprises an electrical conductor having one of its portions (that is, a portion at one side o't the thermocouple joint) provided with an application of metal of a different element from that of the conductor.

It is also sought to provide a thermocouple structure of this character which will permit of the construction of any desired number of identical thermocouple elements in series, by the application of the necessary metallic coating to alternating portions of the conductor simultaneously. n

In carrying out the invention in practice, the method which I have devised for constructing the improved thermocouple element, either singly or in multiple, consists in applying a protective coatingr to a portion or alternating portions of the conductor, and

then subjecting the unprotected portions of the conductor to any well known form of plating means whereby said unprotected portions of the conductor will be coated with the desired metal which will cooperate with .the metal of the conductor in forming the thermocouple joints,

With the foregoing general objects in view, the invention will now be described by reference to the accompanying drawing illustrating certain forms of construction which have devised for embodying the proosed improvements, after which the novel ibatures therein will be particularly set forth and claimed. i

Figure 1 is a face view of a thermocouple structure adapted for the embodiment of the A present invention;

Figure 2 is a sectional view illustrating the same form of thermocouple structure in operative relation to a oint between two p1 e sections; y

igure 3 is a sectional view, partly broken away, representing a section taken on the line III-Ill `of Figure 2;

Figure 4 is a sectional detail view showing a fragment of the thermocouple structure of the form shown in Fi res 1 to 3;

Figure 5 is a face view of a blank used in 1.922. serial No. 569,501.

the construction of a modified form of the invention; and

Figures 6 and 7 are enlarged detail sections taken on the lines VI-VI and VII-VII, respectively, of Figure 5, and showing the structure of the thermocouple after the application of the protective and metallic coatings in accordance with the improved process.

Referring now to the drawing in detail, and more particularly to Figures l to 4, these views illustrate the improved#thermocouple structure as embodied in a coil of suitable The gasket'9 with its conductor 8 may then be subjected to an electroplating treatment, as by dipping the gasket into a suitable electroplatinc bath in a well known manner, for coating the turns of the conductor 8 on the other side of the gasket with a film of appropriate metal, as indicated at 12 in Fi ure 4. whereby the required thermocouple joints 13 and 14 are formed at the inner and outer edges, respectively, of the gasket 9; that is to say, these are joints made by the junctures between two different metals, as represented by the different metals composing the conductor 8 and the film of metal 12. These metalsv may of course be any desired metallic elements, having thermoelectric properties, the only limitation being that the metal selected forlorming the film 12 shall be ofrelatively smaller electrical resistanc'e than the metal composing the conductor 8. Any other known electrical or chemical method may be employed for coating .this film of metal 12 upon the alternate portions of the conductor 8, the electro lating method described being herein set orth as presenting the method probably lending itself best for this purpose. The insulator element to which the conductor 8 is applied as interposed between a pair of insulating v gaskets 15, and these in turn clamped between the flanges 16 at the joint between two pipe sections 17 which are coupled by means of bolts 18 passing through said flanges and through openings 19 provided in the gasket 9. If now, the terminals 10 of the conductor 8 be connected with an ordinary form of millivoltmeter (not'shown), the difference in temperature between the inside and out-- side of the conduit formed by the pipe 17 may be measured with great accuracy, since it 1s apparent that the diderence in potential between the ends of the multiple thermo.

Lcouple structure will correspond directly to the diierence between the temperature existing at the interior thermocouple joints 13 and that of the exterior thermocouple joints 14. I haveA found thatlby the usel of a conductor'8 of nickle alloy composition known commercially as Advance wire, and coating the alternating turns of the coil with a silver plating, and with a suticient number of the thermocouple joints 13 and 14, approximate- -ly as shown by Figure 1, the measuring instrument connected with the terminals 10 will register several-millivolts for each dereeo difference in temperature between the lnside and outside of the pipe 17. If the two metals be so chosen as to produce a still greater ratio of resistance at the joints, and the number of turns of the conductor 8 increased still further, which may4 be done without complicating the method of process, the electromotive force may be proportionately increased for the same ditierence in temperature between the joints 13 and 14.

In Figures 5to 7 I illustrate a modified and even simpler form of construction which may be producedl verycheaply andwill serve equally as eiiiciently where a structure of this type can be used. Instead of coiling the conductor about an. insulator, a zigzag coil of the desired form, as indicated at 8', is stamped from the chosen metal; then each half turn of the conductor is coated with .the ilm 12 of a suitable ditferent metal corresponding tothe film 12 of the first form of construction, as b lirst applying a protective coating 11 to alf of each turn ofthe coil and then subjecting the entire coilv to the electroplating process, as before, for coating the remaining'- h'alf turns with the other metal 12. This results in the forweaves It will thus be apparent thatL I have devised an -extremely\ practical, simple and. efiicient thermoco-uple structure as well as a very economical method of making the same, this process being adapted for producing the thermocouple structure. in practically any form in which it may be required for use.

@ne of the particular points of advantage is i seen in the fact thatL the ordinaryv millivoltmeter may be used for ascertaining the temperat'ures instead ofa otentiometer or other special apparatus, anv in the form of thermocouple structure illustrated for ascertaining the temperatures inside a conduit or vessel, the mode of installation isvastl simplified as compared to methods hereto' oreused, since the present method requires only the replacing of the gasket with the thermocouple gasket and the connection of its terminals tothe measuring instrument, instead of requiring any special boring orwother alteration ot the apparatus to which the thermocouple structure is applied. Ordinary cop- 'per wire is used for making the connectionv between the terminals of the thermocouple structure and the instrument used for determining the temperature, and this instrument A may beplar-ed at any point remote from the thermocouple struct-ure without requiring any compensation on thatyaccount.

struction permits the use of temperature controlling relays without necessitating any magniticati-on of the current or anywiring of auxiliary apparatus.

Agaln the use ofthe improved th'ermocouple con` while i have illustrated and described what I now regard as practical and eiicient modes ofl practicing the invention Ir'desire to reserve the right to makeall suc changes or modifications as may fairly andI properly fall within the lscope of the appended claim.

What I claim is:- i

thermocouple structure comprising a continuous strip of conducting material arranged in the form of a zigzag coil and in a substantially annular outline, alternating semiconvolutions of said coil being provided with applications of met-al of different ,resistance properties from said conducting material.

In Witness whereof I hereunto afx my i signature.

vLADIMVIn K. zwonYKrN. 

